Millions of Americans hailed his election as an end to partisanship, a renewal of the spirit of compromise and a reinvigoration of the nation’s highest ideals at home and abroad.

Above all, as America’s first black chief executive, Obama symbolized the healing of long-festering wounds that were the terrible national legacy of slavery, the Reconstruction Era and Jim Crow. We would be, finally, one nation.

But after nearly four years in office, Obama has become a sharply polarizing figure.